A gas turbine engine generally includes a compressor section, one or more combustors, and a turbine section. The compressor section progressively increases the pressure of air entering the gas turbine engine and supplies this compressed air to the one or more combustors. The compressed air and a fuel (e.g., natural gas) mix within the combustors and burn within combustion chambers to generate high pressure and high temperature combustion gases. The combustion gases flow from the combustors into the turbine section where they expand to produce work. For example, expansion of the combustion gases within the turbine section may rotate a rotor shaft connected to a generator to produce electricity.
One or more flame detectors may be used to determine the presence of a flame (i.e., combustion of the compressed air and fuel mixture) within the combustion chambers. Typically, the flame detectors are positioned on a compressor discharge casing or a combustor casing. This positioning arrangement, however, provides the flame detectors with a limited view of the combustion chamber.